CVE-2025-9860 is a stored Cross-Site Scripting (XSS) vulnerability affecting the Mixtape plugin for WordPress, developed by natata7. This vulnerability exists in all versions up to and including 1.1 of the plugin. The root cause is insufficient input sanitization and output escaping on user-supplied attributes within the plugin's 'mixtape' shortcode. Authenticated users with contributor-level access or higher can exploit this flaw by injecting arbitrary malicious scripts into pages generated by the plugin. These scripts execute in the context of any user who views the compromised page, potentially allowing attackers to steal session cookies, perform actions on behalf of users, or redirect users to malicious sites. The vulnerability has a CVSS 3.1 base score of 6.4, reflecting medium severity, with an attack vector of network (remote exploitation), low attack complexity, requiring privileges (contributor or above), no user interaction, and a scope change indicating that the vulnerability affects components beyond the initially vulnerable plugin. No known exploits are currently reported in the wild, and no patches have been published yet. The vulnerability falls under CWE-79, which covers improper neutralization of input during web page generation, a common vector for XSS attacks. Since WordPress is a widely used content management system, and the Mixtape plugin is used to embed media content via shortcodes, this vulnerability can be leveraged to compromise websites that allow contributors to add or edit content, leading to persistent XSS attacks that affect site visitors and administrators alike.

For European organizations, this vulnerability poses a significant risk especially to those relying on WordPress sites with the Mixtape plugin installed. The ability for contributor-level users to inject persistent malicious scripts can lead to session hijacking, unauthorized actions, and data theft, undermining the confidentiality and integrity of web applications. Organizations handling personal data under GDPR could face compliance issues if user data is compromised through such attacks. Additionally, reputational damage and loss of user trust are likely consequences. The scope change in the CVSS vector indicates that the vulnerability could affect other components or users beyond the initial plugin context, potentially broadening the impact. Since the attack requires authenticated contributor access, insider threats or compromised contributor accounts increase risk. The absence of known exploits in the wild currently reduces immediate threat but does not eliminate the risk, as attackers may develop exploits once patches are available or the vulnerability becomes public knowledge. European organizations with public-facing WordPress sites, especially those in sectors like media, education, and government that often use contributor roles, are particularly vulnerable.

1. Immediately audit WordPress sites to identify installations of the Mixtape plugin and determine the version in use. 2. Restrict contributor-level access strictly to trusted users and review user permissions to minimize the number of users who can inject content. 3. Implement Web Application Firewalls (WAFs) with rules to detect and block common XSS payloads targeting the 'mixtape' shortcode parameters. 4. Employ Content Security Policy (CSP) headers to limit the execution of unauthorized scripts on affected sites. 5. Monitor logs for unusual activity from contributor accounts and unusual content changes involving the Mixtape shortcode. 6. Until an official patch is released, consider disabling or removing the Mixtape plugin if it is not essential. 7. Educate content contributors on safe content practices and the risks of injecting untrusted code. 8. Once a patch is available, prioritize prompt application of updates. 9. Use security plugins that sanitize user inputs and outputs to add an additional layer of defense. 10. Conduct regular security assessments and penetration tests focusing on XSS vulnerabilities in WordPress environments.